GNU Multiple Precision Arithmetic Library (GMP) is a free library for arbitrary-precision arithmetic, operating on signed integers, rational numbers, and floating-point numbers.

The basic interface is for C, but wrappers exist for other languages, including Ada, C++, C#, Julia, .NET, OCaml, Perl, PHP, Python, R, Ruby, and Rust.

GMP aims to be faster than any other bignum library for all operand sizes.

GMP is used for integer arithmetic in many computer algebra systems such as Mathematica[10] and Maple.

GMP is needed to build the GNU Compiler Collection (GCC).